废话不多说了，直接给大家贴代码了，具体如下所示：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
[removed]
var a=0
var test=function(resolve, reject){
setTimeout(function(){
a=4;
console.log(a)
if(a<2>2){reject('400 died');}
},3
